Syntonic signaling system.



No. 797,363. PATENTED- AUG. 22, 1905.

M. MILGH. SYNTONIG SIGNALING SYSTEM.

Inventor.

APPLICATION FILED EAR. 30,1904.

Witnesses.

' Maurice Milch.

UNITED STATES MAURICE MILCI-I, OE SCI-IENECTADY, NEW YORK, ASSIGNOR TOGENERAL PATENT OFFICE.

Specification of Letters Patent.

Patented Aug. 22, 1905.

Application filed March 30, 1904:. Serial No. 200,709.

To ctZZ whom it may concern:

Be it known that I, MAURICE Minor-r, a subject of the King of Hungary,residing at Schenectady, in the county of Schenectady and State of NewYork, have invented certain new and useful Improvements in SyntonicSignaling Systems, of which thefollowing is a specification. I

My invention relates to syntonic signaling systems; and its object is toprovide a system of this nature which may be adapted for use as arailway block-signal system and which shall permit the signal to begiven on the car itself, if desired.

In general my invention consists in impressing upon the power-circuitfor the cars an alternating voltage'of high frequency. Thehigh-frequency signaling-circuit is completed by a circuit on any carwhich is operating on the power-circuit. This circuit on a car isarranged with proper values of inductances and capacity, so that with asingle car-circuit connected to the source the high-voltagesignaling-circuit is resonant and a comparatively large current flows;but when two cars are connected in parallel to the source thehighvoltage signal-circuit is in non-resonant condition and a muchsmaller current consequently flows, which difference may be utilized foroperating a protective device on the car, so giving warning that twocars are in the same block.

My invention will best be understood by reference to the accompanyingdrawing, in which A represents a source of high-frequencyalternating-current voltage, and D represents a source of direct-currentor of low-frequency alternating current. The two are connected inparallel across feeder F and the rail or return conductor R throughdiscriminating devices, such as a capacity C and an inductance I,respectively. Capacity C prevents the flow of direct current or of anyappreciable amount of low-frequency alternating current through thesource A, at the same time ofiering practically no impedance to the flowof high-frequency current, and inductance I prevents the flow of anyappreciable amount of highfrequency current through the source D, whileat the same time oifering practically no impedance to the direct orlow-frequency current. The feeder F is connected, through a series ofinductances c' 2', to the trolley-wire or third ra1l, which is formed asa sectlonal conductor composed of a number of sections T T, insulatedfrom each other.

I have shown two car-circuits in the drawing. The power-circuit passesfrom the trolley-wire T through the switch or circuitbreaker S andthrough the usual controllingswitches (not shown) to the motors M andthence to the rail or return conductor R. The signal-circuit isconnected in parallel with the power-circuit and includes, besides thecondenser 0 c, the protective devicesas, for instance, a coil 8, whichwhen energized holds switch S of the power-circuit closed. Thesignal-circuit on each car has its capacity and inductance soproportioned relative to the in ductances c that when only one car is incontact with one section of the trolley-wire the signal-circuit is intune or resonant, and consequently suflicient current flows through thesignal-circuit to enable coil 8 to hold switch S closed; but if a secondcar enters the block, as is shown in the drawing, the two car-circuitsin parallel produce a non-resonant or untuned condition of thehigh-frequency circuit and the current in the signal-circuit issufficiently reduced for operating the protective devices. Warning isthus at once given that two cars are in the block, and, if desired, thepower-circuit of both cars may be opened by the tripping-coils 8. Thusthe second car will be unable to move until the first car is out of theblock.

It is obvious that a number of variations may be made in the system thatI have shown, different forms of protective devices may be used, and theconnections and arrangements of the circuits varied without departingfrom the spirit of my invention.

Accordingly I do not desire to limit myself to the particularconstruction and arrangement of parts here shown, since changes which donot depart from the spirit of my invention and which are within thescope of the appended claims will be obvious to those skilled in theart.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is-

1. In combination, a railway power-circuit including a sectionalconductor, a source of high-frequency voltage connected to said circuit,car-circuits arranged to produce resonant circuit conditions for saidhigh-frequency circuit when a single car-circuit is connected to asection of said conductor and non-resonant conditions when two or morecar-circuits are connected to one section of said conductor, andprotective devices responsive to said nonresonant conditions.

2. In combination, a railway power-circuit including a sectionalconductor, a high-frequency circuit in parallel therewith, car-circuitsarranged to produce resonant conditions of said high-frequency circuitonly when a predetermined number of car-circuits are connected to onesection of said conductor, and a protective device included in saidhighfrequency circuit.

3. In combination, a railway-circuit comprising a sectional conductorand a continuous conductor, a source of power having its terminalsconnected to said conductors respectively, a source of high-frequencycurrent connected in parallel with said source of power, car-circuitsarranged to produce resonant circuit conditions for said high-frequencysource only when a predetermined number of carcircuits are connected toone section of said conductor, and protective devices included in saidcar-circuits.

4. In a syntonic signal system for railways, a source of high-frequencyvoltage, a sectional conductor connected thereto and arranged to beengaged by moving cars, carcircuits adapted to produce resonant circuitconditions for said source only when a predetermined number ofcar-circuits are connected to one section of said conductor, andprotective devices connected in the car-circuits.

5. In a syntonic signal system for railways, a high-frequencysignal-circuit including a sectional conductor adapted to be engaged bymoving cars, car-circuits arranged to produce resonant conditions insaid high-frequency circuit only when a predetermined number ofcar-circuits are connected to one section of said conductor, and aprotective device responsive to a variation in the amount of current insaid high-frequency circuit.

6. In a syntonic signal system for railwayblocks, a high-frequencysignal-circuit, means for rendering said circuit resonant when apredetermined number of cars are in a block, and a protective deviceresponsive to a variation in the amount of current in said circuit.

7. In a syntonic signal system for railways, a high-frequencysignal-circuit comprising a sectional conductor adapted to be engaged bymoving cars, means for rendering said circuit resonant when apredetermined number of cars engage one section of said conductor, and aprotective device connected in said circuit.

8. In combination, a power-circuit for electric railways including asectional conductor, a source of power connected thereto, a source ofhigh-frequency currentconnected thereto, discriminating devicesconnected between said sources and said circuit, a circuit on each carin parallel with the power-circuit of the car and containing adiscriminating device and arranged to produce resonant circuitconditions for the high-frequency source only when a single car-circuitis connected to one section of said conductor, and protective devices inthe car-circuits.

9. In an electric railway, a sectional conductor, a continuous feedertherefor, induct ances connecting the sections of said conductor to saidfeeder, a source of power connected to said feeder, a source ofhigh-frequency current connected to said feeder, means for producingresonant circuit conditions only when a single car engages one sectionof said conductor, and a protective device responsive to a diminution inflow of current in the highfrequency circuit.

10. In an electric railway, a sectional conductor, a continuous feedertherefor, inductances connecting the sections of said conductor to saidfeeder, a source of power connected to said feeder, an inductance inseries with said source, a source of high-frequency current connected tosaid feeder, a capacity in series with said high-frequency source,carcircuits arranged to produce resonant circuit conditions for saidhigh-frequency source, and protective devices in said car-circuits.

11. In an electric railway, a source of power, a source ofhigh-frequency current, a sectional conductor, inductances connectingthe sections of said conductor to said sources, means for producingresonant circuit condi tions for said high-frequency source when apredetermined number of cars engage one section of said conductor, and aprotective device responsive to non-resonant conditions.

12. In an electric railway, a source of power, a source ofhigh-frequency current, a sectional conductor, inductances connectingthe sections of said conductor to said sources, car-circuits arranged toproduce resonant circuit conditions when a single car-circuit isconnected to one section of said conductor, and protective devices insaid car-circuits.

In witness whereof I have hereunto set my hand this 28th day of March,1904.

MAURICE M ILCH.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

